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Table 2 Final statements on OA phenotypes

From: A consensus-based framework for conducting and reporting osteoarthritis phenotype research

NumberStatementMean scoreDistribution of scores (minimum—25% percentile—75% percentile—maximum)
1OA phenotypes are subtypes of OA that share distinct underlying pathobiological and pain mechanisms and their structural and functional consequences.8660—80—94—100
2OA phenotypes can become apparent in differences in risk factors, prognostic factors, nature and extent of symptoms and signs, disease trajectory, and/or responsiveness to particular treatments or treatment in general.8970—80—99—100
3An OA phenotype classification system is likely to consist of input variables that together reflect (the likelihood of) the presence of one or more pathobiological and pain mechanisms.8870—80—94—100
4Classification systems are likely to use one or more measures from either one or more domains (e.g., imaging markers, biochemical markers, and pain) to identify a clinically relevant OA phenotype or phenotypes.8660—80—95—100
5The potentially identified phenotype(s) should differ from others in terms of clinically relevant disease-driving factors and/or outcomes.8750—80—99—100
6Research efforts may initially lead to multiple proposed phenotype classification systems. Eventually, these should be aligned and come together in one.8465—72—94—100
7aDifferences in the disease stage may cause different results from OA phenotyping studies between study populations. It is likely that the nature and course of disease stages may differ between patients and phenotypes.8250—80—90—100
7bDisease stage(s) of the study population should always be reported. Reasons to take or not take disease stage into account in the analyses (e.g., to adjust for confounding or look for interaction) should be weighted for every study.8450—80—99—100
8aSome components of pathobiological and pain mechanisms in OA may be similar between different joints such as knee and hip (e.g., synovitis, central pain perception), while others may differ (e.g., menisci, femoral head shape). The decision to extrapolate findings from one joint to another, or not, should be justified.8650—80—94—100
8bPhenotype classification systems can be designed for individual joints or systemically (e.g., for multiple joints in one patient), depending on the pathobiological and pain mechanism that is under study and the goal of the study.8670—80—90—100
9Data-driven approaches for constructing phenotype classification systems are generally preferable over expert opinion-based approaches, as long as they are performed using high-quality data and appropriate statistics, are reproducible, and have clinical validity, relevance, and applicability as judged by experts in the field.9170—86—100—100
  1. Overview of the final statements that resulted from the Delphi exercise. The level of agreement among panel members is indicated for every statement by the mean score (0% meaning no agreement and 100% meaning complete agreement) and the distribution of individual scores
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